        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Arial', sans-serif;
        }

        body {
            display: flex;
            flex-direction: column;
            height: 100vh;
            background-color: #f5f5f5;
            position: relative;
            color: #666;
        }

        .tit {
            font-size: 20px;
            font-weight: 400;
            letter-spacing: 0px;
            line-height: 28.96px;
            color: rgba(47, 49, 53, 1);
            text-align: center;
            line-height: 50px;
            margin-left: 10px;
            margin-right: 10px;
        }

        .top-nav {
            display: flex;
            background-color: #fff;
            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
            z-index: 10;
            background: linear-gradient(to left, #e6f7ff, #b6d3eed2);
            height: 50px;

        }

        .top-nav-item {
            padding: 15px 20px;
            cursor: pointer;
            position: relative;
            font-size: 14px;
            color: #666;
        }

        .top-nav img {
            position: absolute;
            width: 40px;
            height: 40px;
            right: 0;
        }

        .top-nav-item.active {
            color: #1890ff;
        }

        .top-nav-item.active::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 3px;
            background-color: #1890ff;
        }


        .task-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 15px 20px;
            background-color: #fff;
            border-bottom: 1px solid #e8e8e8;
            background: linear-gradient(to left, #e6f7ff, #b6d3eed2);
        }

        .task-title {
            font-size: 18px;
            font-weight: 500;

        }

        .export-btn {
            padding: 5px 15px;
            background-color: #1890ff;
            color: white;
            border: none;
            border-radius: 4px;
            cursor: pointer;
        }

        .main-content {
            display: flex;
            flex: 1;
            overflow: hidden;

        }


        .left-nav {
            width: 264px;
            background-color: #fff;
            border-right: 1px solid #e8e8e8;
            display: flex;
            flex-direction: column;
            height: 100%;
            transition: width 0.3s;
            color: #666;
            z-index: 9;
            background: linear-gradient(to top, #e6f7ff, #b6d3eed2);
        }

        .left-nav.collapsed {
            width: 0;
            overflow: hidden;
        }

        .left-nav-item {
            padding: 12px 20px;
            cursor: pointer;
            border-left: 3px solid transparent;
        }

        .left-nav-item.active {
            border-left: 3px solid #1890ff;
            background-color: #f3f6f7b0;
            color: #1890ff;
        }

        .collapse-btn {
            margin-top: auto;
            padding: 15px;
            text-align: center;
            cursor: pointer;
            color: #666;

        }

        .collapse-btn:hover {
            color: #333;
        }

        .content-area {
            flex: 1;
            padding: 20px;
            background-color: #fff;
            overflow-y: auto;
        }


        .add-task {
            position: absolute;
            bottom: 0;
            right: 0;
            width: calc(100% - 264px);
            padding: 15px 20px;
            background-color: #fff;
            border-top: 1px solid #e8e8e8;
            display: flex;
            transition: width 0.5s;
        }

        .left-nav.collapsed~.add-task-container {
            width: 100%;
        }

        .task-input {
            flex: 1;
            padding: 10px 15px;
            border: 1px solid #d9d9d9;
            border-radius: 4px;
            outline: none;
            width: 1584px;
            height: 60px;
        }

        .task-input:focus {
            border-color: #1890ff;
        }

        .publish-btn {
            margin-left: 10px;
            padding: 10px 20px;
            background-color: #1890ff;
            color: white;
            border: none;
            border-radius: 4px;
            cursor: pointer;
        }

        .my progress {
            margin: 0 5px;
        }